Introduction

Within modern smart grid deployments, there are many locations where we will want to install a device but can not since we can not find a local source of electricity to power the device.  Sometimes, we need power line sensors or remote terminal units in rural and remote sites where it is essential to capture measurement values and then transmit them upstream via communication networks to the substation or the network operation centre.  At other times, we want to manage command and control devices so we can turn on and off devices or open and close switches.  Therefore, the challenge is to find a suitable means to derive power sufficient for the functions needed at the remote site.  The answer can lie with energy harvesting.

What is energy harvesting?  Energy harvesting, or energy scavenging, is a process that captures small amounts of energy that would otherwise be lost as heat, light, sound, vibration or movement. It uses this captured energy to:

  • Improve efficiency – e.g. costs would be cut significantly if waste heat were harvested and used to help power a device, such as a microcomputer or microcontroller
  • Enable new technology – e.g. wireless sensor networks

Energy harvesting also has the potential to replace batteries for small, low power electronic devices. This has several benefits:

  • Maintenance free – no need to replace batteries
  • Environmentally friendly – disposal of batteries is tightly regulated because they contain chemicals and metals that are harmful to the environment and hazardous to human health
  • Opens up new applications – such as deploying energy harvesting sensors to monitor remote locations where traditional power sources are not available

Successfully developing energy harvesting technology requires expertise from all aspects of physics, including:

  • Energy capture (sporadic, irregular energy rather than sinusoidal)
  • Energy storage
  • Metrology
  • Material science
  • Systems engineering
  • Systems Integration

Sources for Energy Harvesting

Energy harvesting is the process by which energy readily available from the environment is captured and converted into usable electrical energy. This term frequently refers to small autonomous devices, or micro energy harvesting.  It is deal for substituting for batteries that are impractical, costly, or dangerous to replace. It is not unusual to have it augment batteries too, so they can work in a symbiotic manner in order to provide a continuous source of power that combines or switches from the battery to the alternate power source as necessary to remain operational.  More inventions are being discovered every year so it is a field of great innovation and rapid change that demands attention by Utilities as a means to power new smart grid points of presence.  There are several key sources of alternate power defined below for your consideration.

Light / Solar

Solar power is generated by using solar panels to collect the sun’s rays and convert it into electricity.  There are two main approaches to solar power – photovoltaic (PV) and concentrated solar power (CSP).

PV is the most commonly seen type of solar power.  It is effective for a wide variety of applications from calculators, wrist watches, to power your home.  It can be cost effective and depending upon the location, it can be efficient as an alternate source of power for smart grid applications.  Photovoltaics convert light into electric current using the photovoltaic effect.

CSP is newer technology and has been deployed mainly in larger commercial situations of large scale since it is more costly to build.  Concentrated solar power systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam.

While Utilities make use of massive solar power farms as a source of electricity generation to power the grid itself, this discussion is only considering solar power as a supply of power to energize a smaller device in the field attached to the grid.

Boeing Solar

Some space manufacturers, such as Boeing who make satellites have been working with solar power for decades.  They have invested millions into solar research and are seen as leaders in maximizing efficiency from PV panels.  Boeing has set the record for PV efficiency with 41.6% of the captured sunlight being converted into electricity.

A Boeing subsidiary named, Spectrolab is the world’s leading supplier of multi-junction photovoltaic solar cells, solar panels, searchlights and solar simulators and recently celebrated its 50th anniversary.  Spectrolab products have powered satellites since 1958 and have contributed to the on-orbit success of numerous commercial, national security, and civil space missions.  Spectrolab’s technological advancements have driven space solar cell efficiencies to more than 28 percent.  Today, Spectrolab cells power 60 percent of all satellites orbiting the Earth, as well as the International Space Station.  Spectrolab has made significant investments to meet the increasing demand of the terrestrial concentrator photovoltaic industry and achieved a 40 percent average production efficiency for terrestrial solar cells in 2011.

IBM Solar

IBM Research and Switzerland-based Airlight Energy announced a new parabolic dish that increases the sun’s radiation by 2,000 times while also producing fresh water and air conditioning.

The CPV, which looks like a 33-foot-high sunflower, can generate 12 kilowatts of electrical power and 20 kilowatts of heat on a sunny day — enough to power several average homes.

The mirrors concentrate the sun on the chips to produce electricity.  Normally, the chips would ignite, since they reach temperatures of 1,500 degrees Celsius.  But IBM scientists are taking a page from the supercomputer playbook to keep them at a relatively cool 105 degrees with a water radiator system.

Both of these areas of innovation in PV and CPV will lead to new solutions to power remote smart grid sites.  It will take time for these technological advances to migrate down market for stand alone applications, but in a few years, it is expected that we will see gigantic leaps forward in the use of solar power for energy supply in rural and remote locations to power devices on the smart grid.

Kinetic / Mechanical

The use of kinetic energy or the generation of electricity from movement has been around for over a century.  Movement has been used as a source of energy harvesting for self-winding watches, toys, and a variety of farm appliances.  Today, we see it used in smartphones, wearable technology and tablet computers.

There is motion or movement everywhere in our world.  If we can harvest this movement and convert it into energy, then it can become an alternate source of electrical power for the smart grid.

While the concept of harnessing mechanical energy that would otherwise be wasted to do useful work is very attractive in theory, in practice, we are faced with big challenges.  The biggest is that in physics, there’s no such thing as a free lunch.  If you get energy, you are getting it from somewhere.  So if you generate electricity by harvesting the movements of the transmission lines swinging in the wind between towers, then the lines will eventually become fatigued by these same movements and deteriorate over time necessitating replacement.  One might argue that this would happen anyway, so what is the problem?  While we may aggravate the situation with our resistive loads on the lines or create other issues compared to a line that has no movement generators attached.

So unless you either only need so little energy that the energy source will not notice the difference, like a self-winding / automatic watch, or if you can somehow only activate the kinetic system when you would want to take energy out of the system anyway, you are probably better using the money that you would spend on the kinetic energy-harnessing device and spending it on solar panels. They are likely to produce many more kWh of energy over time than even a well positioned kinetic generator.

Wind Generation

An exception is the wind generator.  Wind is essentially a moving gas and like all matter, it is formed of particles.  Motion means kinetic energy, so what wind turbines do is capture the kinetic energy in the wind.  This energy can then be transferred from one medium into another, namely into electric energy.

There are three essential parts to a wind turbine. The rotor blades act as “barriers” to the wind.  When the wind forces the blades to move, kinetic energy is transferred from the wind to the blades.  Then, the wind-turbine shaft is connected to the centre of the rotor and acts as a bridge between the rotor and the third component, the generator.  When the rotor spins, the shaft spins as well, transferring the wind’s kinetic energy into the shaft’s rotational energy. The shaft then transfers this mechanical, rotational energy from the rotor to the generator.

The generator uses properties of electromagnetic induction to produce electrical voltage.  Voltage is the force that moves electricity from one point to another as electrical current.  The shaft is attached to an assembly of permanent magnets surrounding a coil of wire, so when the rotor spins the shaft, the shaft spins these magnets, generating voltage in this coil. This voltage then drives the electrical current out through power lines for distribution.

The diameter of the rotor determines how much energy a turbine can generate.  The larger the rotor, the more kinetic energy is harnessed.  Furthermore, a larger rotor requires a taller tower, the height of which grants the rotor access to faster winds.

Water Generation

Waves crashing on the beach and rivers rushing through a valley are forces of nature.  The power of moving water is obvious to anyone who has stood amidst breaking waves or struggled to swim against a river’s current.  New technologies can enable us to harness the might of moving water without building new dams that can have major impacts on wildlife and water quality.

The use of water power dates back thousands of years to the water wheels of Ancient Greece, which used the energy in falling water to generate power to grind wheat.  We now are presented with an opportunity to develop a new generation of water power, one that will harness the abundant energy of our oceans and rivers.

Hydrokinetic technologies produce renewable electricity by harnessing the kinetic energy of a body of water, the energy that results from its motion.  Since water is 832 times denser than air, our tides, waves, ocean currents, and free-flowing rivers represent an untapped, powerful, highly-concentrated and clean energy resource.

A simple water wheel or sluice can be constructed near a smart grid site to generate electricity from water flows.

Motion 2 Energy

The Idaho based Company Motion 2 Energy has recently developed a system capable of channelling the energy created by movement into electric energy.  The motion required for generating the energy can be either human or vehicular, and the electric energy can be used in various applications, such as microchips, AA-sized battery, and mobile devices like cellular phones.  In larger scale generators, Motion 2 Energy’s solution can be fitted into any generator using a magnet and coil configuration.

Motion 2 Energy (M2E) is developing a system that transforms kinetic energy into electric power.  Unlike other products of this kind, the M2E system is based on standard components and its manufacturing cost is about the same as that of conventional lithium ion batteries.  M2E’s solution was originally developed at the Idaho National Lab and was initially intended for military use.  Today, heavy batteries are affecting soldiers’ ability to fight. The M2E solution eases soldiers’ weight load and creates a self replenishing source of energy.  M2E’s innovation has to do with the architecture of magnetic coils, but the real breakthrough of their technology is that unlike similar previous innovations, which were limited to a small number of applications, it can be applied to motor generators of every size.

Can this M2E solution be transferred to smart grid applications – yes, it can.  Now, we can not use human or vehicular sources of movement to create the electricity, but we have several things within the smart grid that move, such as transmission lines.

Piezoelectric materials can also be used to harvest low levels of mechanical energy into electrical energy suitable for powering wireless sensors, low power microprocessors or charging batteries.

A vibration powered generator is such a device that permits electricity to be generated in environments that preclude having any electrical connection to the outside world.  Sensors in inaccessible places can now generate their own power and transmit data to outside receivers.

Flywheel

Flywheel systems store energy kinetically rather than chemically. Instead of dozens of 100-pound containers of lead plates submerged in sulphuric acid, flywheels use the inertia of a spinning mass to store and regenerate power.

A high-performance rotor assembly spins up to 16,000 rpm. The rotor assembly is enclosed in a sealed vacuum chamber which provides a near frictionless environment and also eliminates exposure to oxygen and moisture which extends the life of the internal components. To reduce wear and further extend the life of the internal parts while minimizing friction, a magnetic lift system uses a non-contacting magnetic field to fully lift and support the rotor. Top and bottom bearing system ensures the spinning rotor maintains its axis of rotation with extremely low bearing loads. With the ability to perform more than 175,000 full depth charge and discharge cycles, flywheels can outperform and outlast other storage technologies in high-cycle applications, and the robust design minimizes the need for flywheel system maintenance.

It can be fitted to other energy harvesting solutions like solar thermal and Stirling Engines combined with a momentum wheel / flywheel that spins in a vacuum chamber.  The kinetic momentum of the flywheel spins after the source engine stops.  While it will decay in speed over time, the vacuum helps to maintain its spin for extended periods of time.  It is ideal to bridge short-term power outages.

Kinetic energy is roughly equal to mass times velocity squared. So doubling mass doubles energy storage, but doubling the rotational speed quadruples energy storage.

Flywheels are often buried underground to maintain a constant ambient temperature.

Thermal

Almost all coal, nuclear, geothermal, solar thermal electric and waste incineration plants as well as many natural gas power plants are thermal.   Natural gas is frequently combusted in gas turbines as well as boilers. The waste heat from a gas turbine can be used to raise steam, in a combined cycle plant that improves overall efficiency.  Power plants burning coal, fuel oil, or natural gas are often called fossil-fuel power plants. Some biomass-fueled thermal power plants have appeared also. Non-nuclear thermal power plants, particularly fossil-fueled plants, which do not use co-generation are sometimes referred to as conventional power plants.

Commercial electrical utility power stations are usually constructed on a large scale and designed for continuous operation.

But, what about small scale generation?  How can thermal generation be used to generation small amounts of power needed to generate the requisite electricity for a smart grid node, supported by communications equipment for commend and control of reclosers, cap banks, phasers or other critical devices.  These sites need power equal to several small 15 amp circuits, maybe less depending upon the needs of the site and the application.

While many of the listed thermal generation types are not easily scalable nor practical for micro-generation, one or two types may be acceptable.  A clear choice today is solar thermal.

Solar Thermal

Solar thermal is often thought as solar water heating systems.  It use free heat from the sun to warm domestic hot water.  A conventional boiler or immersion heater can be used to make the water hotter, or to provide hot water when solar energy is unavailable.  In many Caribbean and Equatorial countries solar thermal is the main method to generate hot water for bathing and cleaning.  After all, the sun is abundant in this region and traditional sources of electricity are hard to come by in many cases.  One of the hazards of this approach to hot water is the potential for burns and scolding from overheated water.  In North America, it is common to see solar thermal to heat or augment the heating of swimming pools.  So, how can it be used for smart grid?

Once collected as heat, the hot water thermos containment efficiency improves significantly with increased size.  Unlike Photovoltaic technologies that often degrade under concentrated light, Solar Thermal depends upon light concentration that requires a clear sky to reach suitable temperatures.

Heat in a solar thermal system is guided by five basic principles: heat gain; heat transfer; heat storage; heat transport; and heat insulation.  Here, heat is the measure of the amount of thermal energy an object contains and is determined by the temperature, mass and specific heat of the object. Solar thermal power plants use heat exchangers that are designed for constant working conditions, to provide heat exchange. Copper heat exchangers are important in solar thermal heating and cooling systems because of copper’s high thermal conductivity, resistance to atmospheric and water corrosion, sealing and joining by soldering, and mechanical strength. Copper is used both in receivers and in primary circuits (pipes and heat exchangers for water tanks) of solar thermal water systems.

Heat is transferred either by conduction or convection. When water is heated, kinetic energy is transferred by conduction to water molecules throughout the medium. These molecules spread their thermal energy by conduction and occupy more space than the cold slow moving molecules above them. The distribution of energy from the rising hot water to the sinking cold water contributes to the convection process. Heat is transferred from the absorber plates of the collector in the fluid by conduction. The collector fluid is circulated through the carrier pipes to the heat transfer vault. Inside the vault, heat is transferred throughout the medium through convection.

Heat storage enables solar thermal plants to produce electricity during hours without sunlight. Heat is transferred to a thermal storage medium in an insulated reservoir during hours with sunlight, and is withdrawn for power generation during hours lacking sunlight. Rate of heat transfer is related to the conductive and convection medium as well as the temperature differences. Bodies with large temperature differences transfer heat faster than bodies with lower temperature differences.

Heat transport refers to the activity in which heat from a solar collector is transported to the heat storage vault. Heat insulation is vital in both heat transport tubing as well as the storage vault. It prevents heat loss, which in turn relates to energy loss, or decrease in the efficiency of the system.

With solar thermal, electricity can be generated directly or used to augment PV or CPV when the sun is not shining if the hot water is stored for later use for generation.  In this way, around the clock supply of electricity in the 100s to low 1,000s of watts can be generated.

Stirling Engine

The Stirling engine was invented in 1816 by the Rev. Robert Stirling who sought to create a safer alternative to the steam engines, whose boilers often exploded due to the high steam pressures used and limitations of the primitive materials available at the time.  Like other heat engines the Stirling engine converts heat energy into mechanical energy.  The essential features of the Stirling engine however are that it is a closed cycle, external combustion engine.  This means that it uses a fixed amount of working fluid, usually air, but other gases may be used, enclosed in a sealed container and the heat consumed by the engine is applied externally.  This allows the engine to run on just about any heat source including fossil fuels, hot air, solar, chemical and nuclear energy.  It can also work with very low temperature differentials, as low as 7°C, between the heat source and the heat sink so that it can be powered by the difference in temperature between water and air or even in a model similar to geothermal were the difference between air and ground temperature at a set depth are used.

By combining the hot water from solar thermal as well as storage of the hot water for hours when the sun does not shine, this source of heat can be used in conjunction with the air temperature to operate a Stirling Engine rather effectively.

The Stirling Engine relies on the property of gases that they expand when heated and contract when cooled. (Charles Law). If the gas is contained within a fixed volume, its pressure will increase on heating and decrease on cooling.

If the gas is held in a variable volume container, constructed from a movable piston in a cylinder closed at one end, the pressure increases and decreases will cause the piston to move out and in.  Repeated heating and cooling will cause a reciprocating movement of the piston which can be converted to rotary motion using a conventional connecting rod and a crankshaft with a flywheel.

Unfortunately the rate at which the temperature of the gas can be varied by heating and cooling the cylinder is limited by the large thermal capacity of practical pistons and cylinders.   This problem however can be overcome by maintaining one end of the cylinder at a constant high temperature and the other end at a constant cold temperature and moving the gas from one end of the cylinder to the other.  This is accomplished by means of a loose fitting piston, known as the displacer, which moves back and forth inside the cylinder, thus shuttling the gas from one end to the other.  As the displacer moves, the gas leaks around the gap between the displacer and the cylinder wall.  The displacer produces no power itself and only uses enough energy to circulate the gas within the cylinder. Power is extracted from the thermal system by using the volume/pressure variations of the gas at the cold end of the cylinder to push a separate “power piston” back and forth. Many different piston and displacer configurations are possible and examples illustrating the most common types are given below.

The Stirling Engine is my personal favourite device to manufacturer energy from the environment.  It is a brilliant piece of technology and is simple to build, use and maintain.

Geothermal

Geothermal Energy is heat (thermal) derived from the earth (geo).  It is the thermal energy contained in the rock and fluid (that fills the fractures and pores within the rock) in the earth’s crust.

To develop a geothermal power, you need to drill a well deep into the ground to extract hot water to generate steam to turn an electrical turbine. The water is then recycled through another well back underground.  The most important factors are the temperature of the extracted water and the flow rate – the hotter the water and the more of it, the better.

Direct use, as the name implies, involves using the heat in the water directly (without a heat pump or power plant) for such things as heating of buildings, industrial processes, greenhouses, aquaculture (fish farming) and resorts.  Direct use projects generally use resource temperatures between 38°C (100°F) to 149°C (300°F). Current U.S. installed capacity of direct use systems totals 470 MW or enough to heat 40,000 average-sized houses.

Geothermal Heat Pumps use the earth or groundwater as a heat source in winter and a heat sink in summer.  Using resource temperatures of 4°C (40°F) to 38°C (100°F), the heat pump, a device which moves heat from one place to another, transfers heat from the soil to the house in winter and from the house to the soil in summer.  Accurate data is not available on the current number of these systems; however, the rate of installation is thought to be between 10,000 and 40,000 per year.

Geothermal heat pumps when used with other technologies can generate electricity.  Again this may be a good combination with a Stirling Engine for small scale electricity generation needed at smart grid locations.

Electromagnetic

The basic law of electromagnetic induction states that whenever a conductor (copper wire) passes through magnetic lines of flux, a voltage is induced into the conductor.

Whether you have motion in the magnet or motion in the conductor, electromagnetic induction will occur.  This is the very process by which we receive electricity in our homes.  Large generators are used that basically consist of a large coil of wire and a large magnet. One or the other is then put into motion usually by rotation.

As a result of the motion, electromagnetic induction is now taking place and a voltage is being induced into the copper wire and sent on down the line where it will be used for a light bulb or a microwave.

Mutual inductance occurs when two circuits are arranged so that the change in current in one causes an emf to be induced in the other.

Leaching / Induction

A German student has built an electromagnetic harvester that recharges an AA battery by soaking up ambient, environmental radiation.  These harvesters can gather free electricity from just about anything, including overhead power lines, coffee machines, refrigerators, or even the emissions from your WiFi router or smartphone.

Student Project

This might sound a bit like hocus-pocus pseudo-science, but the underlying science is actually surprisingly sound.  We are, after all, just talking about wireless power transfer –  just like the smartphones that are starting to ship with wireless charging technology, and the accompanying charging pads.

In a commercial sense for smart grid devices, we can do a similar thing and harvest power via induction directly from power lines and transformers.

Wireless power transfer or wireless energy transmission is the transmission of electrical power from a power source to a consuming device without using solid wires or conductors.  It is a generic term that refers to a number of different power transmission technologies that use time-varying electromagnetic fields.  Wireless transmission is useful to power electrical devices in cases where interconnecting wires are inconvenient, hazardous, or are not possible.  In wireless power transfer, a transmitter device connected to a power source, such as the mains power line, transmits power by electromagnetic fields across an intervening space to one or more receiver devices, where it is converted back to electric power and utilized.

Wireless power techniques fall into two categories, non-radiative and radiative. In near-field or non-radiative techniques, power is transferred over short distances by magnetic fields using inductive coupling between coils of wire or in a few devices by electric fields using capacitive coupling between electrodes.

A current focus is to develop wireless systems to charge mobile and hand-held computing devices such as cellphones, digital music players and portable computers without being tethered to a wall plug.  In radiative or far-field techniques, also called power beaming, power is transmitted by beams of electromagnetic radiation, like microwaves or laser beams.  These techniques can transport energy longer distances but must be aimed at the receiver.  Proposed applications for this type are solar power satellites, and wireless powered drone aircraft.  An important issue associated with all wireless power systems is limiting the exposure of people and other living things to potentially injurious electromagnetic fields.

The electrodynamic induction wireless transmission technique relies on the use of a magnetic field generated by an electric current to induce a current in a second conductor. This effect occurs in the electromagnetic near field, with the secondary in close proximity to the primary. As the distance from the primary is increased, more and more of the primary’s magnetic field misses the secondary. Even over a relatively short range the inductive coupling is grossly inefficient, wasting much of the transmitted energy.

This action of an electrical transformer is the simplest form of wireless power transmission. The primary coil and secondary coil of a transformer are not directly connected; each coil is part of a separate circuit. Energy transfer takes place through a process known as mutual induction. Principal functions are stepping the primary voltage either up or down and electrical isolation. The main drawback to this basic form of wireless transmission is short range. The receiver must be directly adjacent to the transmitter or induction unit in order to efficiently couple with it.

Common uses of resonance-enhanced electrodynamic induction are charging the batteries of smart grid devices such as those used to support microcomputers, microcontrollers, and sensors.  A localized charging technique selects the appropriate transmitting coil in a multilayer winding array structure.  Resonance is used in both the wireless charging pad (the transmitter circuit) and the receiver module (embedded in the load) to maximize energy transfer efficiency.  Battery-powered devices fitted with a special receiver module can then be charged simply by placing them on a wireless charging pad.  It has been adopted as part of the Qi wireless charging standard.

This technology is also used for powering devices with very low energy requirements, such as Internet of Things devices.

RF Harvesting

A novel technology that is emerging is the ability to harvest energy from radio frequency signals already in the air.

RF energy is currently broadcast from innumerable numbers of radio transmitters around the world, including mobile telephones, hand-held radios, mobile base stations, and television / radio broadcast stations. The ability to harvest RF energy, from ambient or dedicated sources, enables wireless charging of low-power devices and has resulting benefits to product design, usability, and reliability.  Battery-based systems can be trickled charged to eliminate battery replacement or extend the operating life of systems using disposable batteries.  Battery-free devices can be designed to operate upon demand or when sufficient charge is accumulated. In both cases, these devices can be free of connectors, cables, and battery access panels, and have freedom of placement and mobility during charging and usage.

The obvious appeal of harvesting ambient RF energy is that it is essentially “free” energy.  The number of radio transmitters, especially for mobile base stations and handsets, continues to increase.  ABI Research and iSupply estimate the number of mobile phone subscriptions has recently surpassed 5 billion, and the ITU estimates there are over 1 billion subscriptions for mobile broadband.  Mobile phones represent a large source of transmitters from which to harvest RF energy, and will potentially enable users to provide power-on-demand for a variety of close range sensing applications.  Also, consider the number of WiFi routers and wireless end devices such as laptops.  In some urban environments, it is possible to literally detect hundreds of WiFi access points from a single location.  At short range, such as within the same room, it is possible to harvest a tiny amount of energy from a typical WiFi router transmitting at a power level of 50 to 100 mW.  For longer-range operation, larger antennas with higher gain are needed for practical harvesting of RF energy from mobile base stations and broadcast radio towers. In 2005, Powercast demonstrated ambient RF energy harvesting at 1.5 miles (~2.4 km) from a small, 5-kW AM radio station.

RF energy can be broadcast in licensed exempt bands such as 868 MHz, 915 MHz, 2.4 GHz, and 5.8 GHz when more power or more predictable energy is needed than what is available from ambient sources.  At 915 MHz, government regulations limit the output power of radios using unlicensed frequency bands to 4W effective isotropic radiated power (EIRP), as in the case of radio-frequency- identification (RFID) interrogators.

Ambient radio waves are universally present over an ever-increasing range of frequencies and power levels, especially in highly populated urban areas.  These radio waves represent a unique and widely available source of energy if it can be effectively and efficiently harvested. The growing number of wireless transmitters is naturally resulting in increased RF power density and availability.  Dedicated power transmitters further enable engineered and predictable wireless power solutions.  With continued decreases in the power consumption of electronic components,  increased sensitivity of passive receivers for RF harvesting, and improved performance of low-leakage energy storage devices, the applications for wire-free charging by means of RF-based wireless power and energy harvesting will continue to grow.

Summary

Energy harvesting is emerging as a valid and reasonable approach to powering low energy consumption devices such as those used in the Internet of Things networks for smart grids.

There are a wide variety of technologies emerging or maturing that make this approach cost effective and reliable.

As devices advance and new circuit designs draws less power, the loads are being reduced while the sources of energy are increasing.  To further benefit, many Internet of Things devices go into various modes of sleep whereby the consumption of power is minimal and sporadic.

The timing is now right to consider alternate sources of power generated from an energy harvesting approach.  Harvesting or scavenging energy from sources that would otherwise be lost as heat, light, sound, vibration or movement is the next great advancement for the smart grid.

References

  1. Institute of Physics – http://www.iop.org/resources/energy/
  2. Texas Instruments – http://www.ti.com/lsds/ti/apps/alternative_energy/harvesting/overview.page
  3. Wikipedia: Solar Power – http://en.wikipedia.org/wiki/Solar_power
  4. Boeing: Solar Power Satellite – http://www.boeing.com/history/products/solar-power-satellite.page
  5. ComputerWorld – http://www.computerworld.com/article/2687236/ibms-solar-concentrator-can-produce-energy-clean-water-and-ac.html
  6. Treehugger – http://www.treehugger.com/renewable-energy/what-kinetic-energy-can-harnessed-power-our-stuff.html
  7. The Future of Things – http://thefutureofthings.com/3297-power-through-movement-technology/
  8. Why-Sci – http://why-sci.com/wind-power/
  9. Hydrokinetics – http://www.ucsusa.org/clean_energy/our-energy-choices/renewable-energy/how-hydrokinetic-energy-works.html#.VTOlq5NCVeo
  10. Wikipedia: Thermal Power Station – http://en.wikipedia.org/wiki/Thermal_power_station
  11. Wikipedia: Solar Thermal Energy – http://en.wikipedia.org/wiki/Solar_thermal_energy
  12. Geothermal Resource Center – http://www.geothermal.org/what.html
  13. Electromagnetic Induction – http://www.missouripermaculture.com/2011/01/generating-your-own-electricity.html
  14. Wikipedia: Wireless Power – http://en.wikipedia.org/wiki/Wireless_power
  15. Mouser – http://ca.mouser.com/applications/rf_energy_harvesting/
  16. Beacon Power – http://beaconpower.com/carbon-fiber-flywheels/

 

——————MJM——————

Michael Martin has more than 35 years of experience in broadband networks, optical fibre, wireless and digital communications technologies. He is a Senior Executive Consultant with IBM’s Global Center of Excellence for Energy and Utilities. He was previously a founding partner and President of MICAN Communications and earlier was President of Comlink Systems Limited and Ensat Broadcast Services, Inc., both divisions of Cygnal Technologies Corporation. He holds three Masters level degrees, in business (MBA), communication (MA), and education (MEd). As well, he has diplomas and certifications in business, computer programming, internetworking, project management, media, photography, and communication technology.